[Milsurplus] RU-16/CW46051A

[Hue Miller]

If it's a museum piece, best have a pre-estate sale or at least  put it behind glass, 
where it won't get touched.
If "useful", as in "useful ham equipment", is key, best stay with TenTec and Yaesu.
If you think it fun & wholesome to recreate the "experience of historic communications",
not just a static display, then sometimes these equipments need some help. We are
not talking a Conversion Manual process here. Even using the RU in CW mode, an
external audio filter is not a bad idea.
If it's the last B-29 or the last RU in the world, i might want to think twice about actually
flying it. -Hue Miller